It is important to remember that left lower lobe pulmonary vessels should be able to be traced through the cardiac shadow on a PA chest x-ray. In this case the vessels cannot be traced and instead air bronchograms are seen consistent with consolidation (left lower lobe pneumonia). The medial portion of the left hemidiaphragm is also obscured. Consolidation in this area is easily missed on frontal projections by inexperienced readers and therefore it's an important check area to remember.